TCP Performance Evaluation over Backpressure-based Routing Strategies for Wireless Mesh Backhaul in LTE Networks

Wireless redundant networks are expected to play a fundamental role to backhaul dense LTE networks. In these scenarios, backpressure-based routing strategies such as BP-MR can exploit the network redun- dancy. In this paper, we perform an exhaustive performance evaluation of different TCP variants over an LTE access network, backhauled by various routing protocols (including per-packet and per-flow BP-MR variants and a static alternative, OLSR ) over two different wireless topologies: a regular mesh and an ir- regular ring-tree topology. We compare the performance of different TCP congestion control algorithms based on loss (NewReno, Cubic, Highspeed, Westwood, Hybla, and Scalable) and delay (Vegas) under dif- ferent workloads. Our extensive analysis with ns-3 on throughput, fairness, scalability and latency reveals that the underlying backhaul routing scheme seems irrelevant for delay-based TCPs, whereas per-flow variant offers the best performance irrespective of any loss-based TCP congestion control, the most used in the current Internet. We show that BP-MR per-flow highly reduces the download finish time, if com- pared with OLSR and BP-MR per-packet , despite showing higher round-trip-time.